Gravity Revealed
Show Title： Gravity Revealed
Rating： Universal
Running Time： 25 minutes
Genre： Science Documentary
Resolution： 4K Domemaster
Audio： Stereo or multitrack (surround)
Trailer: FLV / QuickTime / WMV
Script: PDF
It is one hundred years since the arrival of general relativity, but gravity is still widely misunderstood as the pull of the Earth, or as a mysterious attraction across distance. In “Gravity Revealed” we attempt to replace this mistaken belief with the correct version – gravity is the direct result of warped spacetime.
Aristotle’s Mistaken Legacy
In the fourth century BC the greek philosopher Aristotle provided what was believed to be a definitive explanation of gravity. The universe is made up of five elements – earth, water, wind, fire and an unchangeable, heavenly element named aether. Objects that contain the most earth tend to fall towards the centre of the universe, meaning heavier objects fall faster. Unfortunately, Aristotle’s mistaken interpretation stood as fact for almost two thousand years.
The Insights of Galileo Galilei
The experiments of sixteenth century scientist Galileo Galilei gave us our first real insight into the nature of gravity. If Earth had no atmosphere, all objects would in fact fall at the same rate of acceleration. Dropped from the same height, an elephant would reach the ground at the same time as a feather. Galileo also showed that motion due to gravity is independent of other motion. A cannonball fired parallel to the ground will land at exactly the same time as one merely dropped from the same height as the cannon’s barrel.
Newton’s Law of Universal Gravitation
In the seventeenth century, our view of the universe changed. Newton suggested that all objects with mass create gravity, and correctly identified gravity as being responsible for the motion of celestial bodies in the heavens, as well as for objects falling on Earth. The Moon is forever falling towards the Earth and the Earth is forever falling towards the Sun. Newton was not, however, able to provide an explanation of how gravity actually works. We had to wait until the early twentieth century for the answer.
Einstein Reveals Gravity’s True Nature
The secret of gravity was revealed to us by Albert Einstein in 1915. Einstein’s theory of general relativity showed us that gravity is not an attractive force mysteriously working over distance to draw objects together. Gravity is a natural result of distorting spacetime. All objects with mass distort spacetime, and all objects follow paths through that distorted spacetime. Distorted spacetime is invisible. We can only observe the effects. The Earth is not attracting us. We are endlessly falling into the distortion created by Earth’s gravity, and the ground is stopping our descent.
Scientific Supervision:
Hiroshi Ooguri (California Institute of Technology, Tokyo University)